The design and operation of air conditioner (AC) and heat pump (HP) units are well-known. The application of combination AC/HP units for use in areas outside of homes including but not limited to, vehicles such as recreational vehicles (RVs) such as vans, trailers, motor homes, fifth wheelers, etc. is also well-known. For purposes of example only and not by way of limitation, AC/HP units used with RVs are typically mounted on the roof with few, if any, exceptions. A problem exists with the roof mounted AC/HP units however in that these roof-mounted AC/HP units inherently produce aerodynamic drag and, subsequently, decrease fuel economy. Further, roof mounted AC/HP units require ladders or scaffolding for installation, service and/or removal. In an attempt to reduce problems associated with roof mounted AC/HP units, modern roof mounted AC/HP units feature low-profile designs. These low-profile units are designed to reduce aerodynamic drag but in doing so the AC/HP units suffer a reduction of efficiency because the AC/HP unit condenser and operator coil sizes are reduced. In the end, even the low-profile units create aerodynamic drag and, worse, cause a serious reduction in the operating capabilities of the AC/HP unit.
Likewise, the design and operation of refrigerators, either of the mechanical type with electric motor, compressor, fans, etc. or a piezo-electric type with no moving parts (unless a blower fan is added), or an absorption system type with no moving parts, is well-known. Early mechanical type refrigerators mounted condenser coils on the rear or top of the unit for heat to be dissipated by convection. Modern mechanical type refrigerators mount condenser coils within a duct ventilated by an electrically powered fan to force airflow over the coils and, subsequently, improve the efficiency. Absorption system refrigerators (ASR) are widely used in vehicles and depend on convection induced by heated air to dissipate the heat of the condenser and absorber. Unfortunately, the recovery time of an ASR is a major problem. Typically, the recovery time of an ASR is on the order of one hour of recovery required for every minute the refrigerator door is left open. By comparison, the mechanical type refrigerator has a recovery time of fifteen to twenty minutes.
By way of example only, and not by limitation, ASR's are commonly found in RVs. Wherever they are located, ASR's require a vertical duct or shaft at the rear of the refrigerator to enclose the boiler, condenser, and absorber components of the ASR. The duct or shaft has an external intake and an external exhaust opening or port with grills at the bottom and top of the shaft, respectively, and are ventilated outside of the RV. ASR's operate most efficiently when the differential between the condenser coil temperature and the external ambient air is greatest as in colder seasons. Conversely, the ASR's operate least efficiently when the temperature differential is minimal as in the hotter seasons. Further, the boiler of the ASR's may be heated by electrical coils or a burner using propane, kerosene, or some other acceptable fuel. Unfortunately, the burner flame is vulnerable to gusts and fast flowing air currents. In order to protect the burner from air currents, among other things, typically the vertical duct or shaft at the rear of the ASR (that contains the boiler, absorber, and condenser) has no mechanism for enabling or allowing the introduction of forced air to the system so as to enhance the operational capabilities of the ASR system.
Other significant issues are at play in the tension between efficient operation of AC/HP and refrigerator systems, particularly, for example only, in use with vehicles such as RVs. The rising cost of fuel, for example, has led RV manufacturers to adopt strategies to increase the efficiency and decrease the operating cost of RVs. A major initiative by these manufacturers is to use lighter materials to reduce the weight of the vehicle so that weight is less of the penalty. That is to say, a lighter RV uses less fuel and so forth. Unfortunately, this lighter weight creates a new penalty. If, as is customary in the prior art, the AC/HP unit remains in its usual roof mounted location while at the same time the RV itself is lightened, then the RV center of gravity is incrementally raised. As a result, the stability of the RV is decreased and the tendency of the RV to roll is increased.
Still further, it should be known that roof mounted AC/HP units have a major flaw when operating in the heating mode. That is, in this situation, if the unit is exposed to an unseasonable ice or snowstorm, then the grills and coils of the unit become obstructed, frequently, with snow and/or ice and the unit is rendered useless.
Thus, there is a need in the art for more efficient AC/HP units and refrigerators, for use with vehicles in particular, which simply, easily, and inexpensively address the above stated problems. It, therefore, is an object of this invention to provide an improved combination AC/HP-refrigerator apparatus and method which eliminates aerodynamic drag, results in a more efficient AC/HP system and, at the same time, a more efficient refrigerator system, lowers the center of gravity, increases stability, decreases the tendency of vehicles to roll and eliminates the possibility of bad weather malfunction.